The purpose of the Quality Control Unit (QCU) is to plan, coordinate, and implement a comprehensive program in quality control which assesses and insures completeness, accuracy, timeliness, and representativeness of data available to the NCI that are used to measure the progress of cancer control. A secondary purpose of the QCU program projects is to reduce the variability in procedures and interpretations of data collection and abstracting conventions by individuals responsible for obtaining and managing cancer surveillance information. Thus, education, training and communications are an integral part of the contractor's workscope. A third purpose of QCU is to provide a research evaluation and component focused on assessment of the utility of surveillance data and the efficiency of existing surveillance systems to assure that they continue to serve the NCI program needs. The QCU makes a significant contribution to the National Cancer Program by successfully carrying out work in conformance with these objectives.